Restrictions for IPv6 Multicast Routing
In Cisco Catalyst 9600X Series Switches, source and group addresses are compressed to 32 bits each for creating (S, G) entries. Specifically, the last 32 bits of the group address are used for programming. However, multicast traffic for both FF1E::1 and FF2E::1 will hit the same multicast entry. When both the receiver and source are active for the FF1E::1 group address, the system installs (*, G) and (S, G) entries for this group. When traffic is received for FF2E::1, a lookup is done using the last 32 bits of FF2E::1. However, this lookup matches the entry for FF1E::1, leading to the traffic being forwarded instead of dropped. Review and modify the programming logic to ensure accurate forwarding of multicast traffic for distinct group addresses like FF1E::1 and FF2E::1. This may involve refining the process of selecting and utilizing the last 32 bits for programming the group address.